Telephone system



, V 1,633,116 June 21 1927. I c E. LOMAX TELEPHONE SYSTEM Original Filed Feb. 16. 1923 3 Sheets-Sheet 1 2/ 22 I3 24 I! 26 17 2a 29 50 5/ 52 33 11 -Inusn ur- IZa mza E Lumax ZZ.M

1,633,116 J 21, 1927- c. E. LOMAX wswraous SYSTEM Original Filed Feb. 16. 1923 3 Sheets-Sheet 2 I] reuse ELumsx 1,6 3,116 1 June 21, 1927. c E. LoMAx V 3 TELEPHONE SYSTEM Original Filed Feb. 16. 1923 s Shets-Sheei 5 Inuanc1r-.- I

. I anus ELumax Patented June 21, 1927.

stares eATanr ounce."

CLARENCE E. LOMAX, OF CHICAGO, ZLLINOES, ASaGNOR, BY 'MESNE ASSIGNME NTS,

T0 AUTQMATIC ELECTRIC 1116., 0F CHICAGO, ILLINOIS, A CORPORATION. OF DELA- WARE.

TELEPHONE ESYSTEM.

Application filed. February 1-6, 1923, Serial No. 619,377. Renewed November 26, 1926.

The present invention relates in general to telephone systems and particularly to a new and improved method of obtaining connection between a calling and a called line.-

It sometimes occurs that a subscriber at a given substation may have occasion to call a certain list of telephones at very frequent intervals. hen this is the case, the delay incident to the operation in manual systems, or the labor occasioned by the calling device in automatic systems, may prove burdensome. lhe object of the presentinventi'on' is to provide means, preferably an automatic progressively movable switch whereby the subscriber at a special substation may obtain connection with any one oi a limited number of other stations as-the result of merely depressing a single key, the switch in no manner interfering with the ordinary operation of the telephone. 7

The above object could be accomplished simply by providing an operating conc.uctor from the exchange to the special substation for each line to which special service was desired, were it not for the fact hatthe large number of conductors required would render the system commerci-al'ly impracticable. The present invention utilizes the well-known fact that a plurality of units taken in combination will afi'ord a number of combinations greatly in excess of the number of units. For instance, the units A, C, and 1) taken in pairs afford sir; combinations as follows: AB, AC, AD, BC, RD, and CD. This fact is made use of by providing a plurality of operating conductors between the exchange and the special substation. Atthe exchange each conductor is connected through a relay to main battery. By grounding the operating conductors in con'iliiination, the associated relays can be utilized to set up as many distinct circuits as there are combinations in the particular scheme used. The circuits so set up can be utilized to control the special snitch in the establishment of connect-ions from the special substation to the substation to which the switch has access.

The invention is disclosed in connection with an automatic telephone system, but it is to be understood that it is equally applicable to other systems as well.

The object of the invention will be more fully pointed out hereinafter, reference be i had to the accompanying drawings,

A? Figs. 1, 2, and 3, which, when placed 111 order, show by means of theusual circuit diagrams sufiicient of the apparatus employed in a system embodying the-principles of the invention to enable the same to be understood.

Figure 1 shows the special substation A and a called substation A, together with the keys associated with the special substation.

Figure 2 shows by diagrammatical indicati-on the automatic switches which are normally usedwhenestablishing a connection fromstation A to station A, together with the relays R to- R, inclusive, each of which is associated with: an operating conductor leading to substation A.

Figure 3 shows a switchS which operates to extend thetalki-ng conductors of Station A into engagement with the talking conductors of certain station-s, together with the relay equipment F which serves to control the switch S.

Referring to Fig. 1, the automatic substations A and Aare ordinary automatic substations having the usual talking,- signal- 30 lin I and impulse sendin instrumentalities- .b? 5 Substation A s a special'substation and-has nonnted in close proximity thereto the keys K. Each key, represents a certain substation, connection-to which can be obtained by the simple act of depressing the key. The keys are of the locking type, and are not restored until the conversation 18 completed. A special ringer 35 is provided at substation A which gives notification when, the 9 called party answers a connection set up by means of one of the keys 'When the conversation is completed and the receiver restored at the called substation, the ringer 35 will again operate until the key K has been restored. Conductors" 36 and 37 are the usual talking conductors associated with substation A. Conductor 38 connects the ringer 35 with the central oliice apparatus;

Conductors 39 to 45-, inclusive, are the opcrating conductors connecting the keys K with the central ofliceapparatus. Conductors 456 and 47 are the usual talking conductors associated with substati'on'A. I

Referring to Fig. 2, the line switches C andG, which are denoted by dotted: rem

" which direct service is desired.

tangles, may be assumed to be of the wellknown rotary type. The selector E and the connector H, which are denoted by dotted rectangles, may be assumed to be of the well-known vertical and rotary type.

The operating conductors 39 to L5, inclusive, are shown as terminating in the relays R to R respectively. The invention is illustrated by the use of seven conductors working in combinations of three; it is to be understood, however, that other numbers and combinations are equally applicable. The seven conductors working in triplets attord a total of thirty-four combinations. therefore, thirty-tour keys are provided at substation A. The keys K control the operation of the relays R to R inclusive. in such a way that any conductor in the group 101 to 1534. inclusive, may be grounded.

The talking conductors 36 and 37 are normally connected to line switch C through the resting contacts of relay 135. Conductors 136 and 1.37 extend the talking conductors from substation A to the connector line bank in the usual manner. Conductor 138 is connected to the contact in the connector test bank associated with substation A.

Talking conductors 46 and A? of substation A are connected to the line switch C. Conductors 139 and 1A0 extend the talking conductors to the connector line bank in the usual manner. Conductor l ll connects the contact in the connector test bank associated with substation A with the cut-oft relay of line switch C.

Referring to Fig. 3, the finder switch S is astep by step rotary switch or" the type in which the wipers move in a forward direction only. In -further explanation, it should be stated that this switch is of the type in which the wipers are advanced when the stepping magnet retracts its armature, rather than when the stepping magnet is energized.

To the contacts in the bank accessible to wiper 201, and in the bank accessible to wiper 204 are connected. respectively. multiples of the positive and negative talking conductors of those substations to which directservice is desired. The contact in the bank to which wiper 203 has access are con nected to the test contacts in the connector hank associated with those substations to The contacts in the bank to which wiper 202 has access are extended to certain of the conductors 101 to 1534, inclusive. Fig.

The relay equipment l controls the tinder switch S. and serves to complete the connection. The generator G and the interrupter I together constitute the usual ringing means found in an automatic ottice. The-generator G" is provided to actuate the ringer 35 at substation A. The usual busy machine is indicated. The interrupter T produces a tone which advises the called subscriber that he is being called from a special substation.

The normal operation of extending a connection to substation A from substation A may be described as follows: it being as sumed that the call number of substation A is 878. lVhen the receiver at substation A is removed, the line switch operates to extend the connection to an idle first selector, such as the selector E. The operation 01" the calling device for the first digit 8 will cause the selector E to raise its wipers opposite the eighth level of bank contacts, whereupon the selector will automatically rotate in search of an idle trunk line leading to a connector. It may be assumed that the connector H is the first found to be idle. The operation of the calling device for the second digit 7 will cause the connector H to raise its wipers opposite the seventh level oi bank contacts. The operation 01": the calling device for the third digit 6 will cause the connector H to rotate its wipers into engagement with the bank contacts asso ciated with the called substation A.

The operation of calling substation A from substation A by means of the special apparatus will be described in a general way; it being assumed that substation A is one of the group of substations to which direct service is rendered.

Lh-e calling subscriber at substation A first operates the locking key associated with station A. As a result of this operation, three relays of the RR group operate to ground a certain contact in the bank to which wiper 202 of switch S has access. The tinder switch S thereupon advances its wiper 202' into engagement with that contact. The relay equipment F then tests the called line and. if idle, closes a circuit through wiper 203 to operate the cut-oil. relay ot the line switch associated with substation A. Relay equipment F then rings the called line over \VlDElS 201 and 204-. hen the connection is established, current from generator l causes the ringer at substation A to sound, when the called party answers, the ring ceases as an indication that the called party has answered. At the some time an identity tone is placed on the called line to indicate that the call is 'troin a special substation. When the conversation completed, the subscribers will restore their re ceivers, whereupon the ringer 35 will again operate as a reminder that. the key it. must be restored. lVhen the key K is restored, certain relays in the relay group i? dc-energize and open the circuit to wipers 201, 203, and 204-, whereupon the cl1t-otli relay of the called line switch deenergizes and restores; the called line to normal.

The system having been described in general, a detailed description will. now be given of its operation. For this purpose, it will.

I l t) circuitmay lever of key K spring 49, conductor 41,-

be assumed that key K is associated with the called station Aw When key K is depressed, three circuits are closed, the first circuit extends from ground at the lever of key K spring 48, conductor -39, relay B, through relay 135 to negative battery. The second be traced from ground at the relay R through relay 135to negative battery. The third circuit ground at the lever of key K", spring 50, conductor 45, relay, R through relay 185 to battery.

Relays R, over the above traced circuits. tion of relays R,-R and R causes a ground R R and 185 will energize to be placed upon the thirteenth contact in the bank accessible to wiper 202 of switch- S. The above circuit is traceable from ground at working contact and armature 143 of relay R, armature 144 and working contact of relay R working contact and armature 145 of relay H conductor 109 to the thirteenth contact in thebank accessible to wiper 202. 7

Relay 135, upon energizing, places ground upon the test contact associated with substation A in the connector test bank by way of armature 146 and conductor, 138, thus protecting the calling line in theusual manner. Relay 135 at the same time disconnects the talking conductors 36 and 87 from the extends them by way of line switch G and armatures 147 and 148, conductors 149 and 150 to armatures 205 and 206, respectively, of relay 207 of relay equipment F. A fur ther result of the energization of relay 135 is the closure of a circuit traceable froi'n ground, working contact and armature 151, conductor 152, armature 208 and its resting contact, armature 209, and its resting contact, relay 210, to battery. Relay 210 will now energize and slow acting relay 211 in parallel with the stepping magnet 212 by way of arniiature 213. The stepping magnet now energizes and opens the circuit of relay 210 at armature 209, whereupon relay 210 will dcenergize and open the circuit of the stepping magnet. The stepping magnet, upon deenergizing, advances the wipers one step and again closes the circuit of relay 210. The alternate operation of relay 210 and the stepping magnet will continue until the wiper 202 engages a grounded bank contact. As the relay 211 is slow acting, it will not deenergize during the momentary deenergization of relay 210.

Then wiper 202 engages the thirteenth bank contact, a circuit is established from grounded conductor 109, thirteenth bank contact, wiper 202, relay 207 to battery. Relay 207 will now operate and permanently open the circuit to relay 210 at armature 208.

may be traced fronr The operainterru'pter contacts resting armature 221, armature .222

close a circuit through It may be assumed that the called line is idle and, when relay 211 deenergizes shortly after the last deencrgization of relay 210, a circuit may be traced from grounded conductor ,152, armature 208 and its working contact, armature 214 and its restmg contact, upper conductor 152. The complete energization of relay 215 places direct ground on conductor 142 at armature 'the bridge cut-oil relay switch, and grounding 218, thus maintaining of the called line the associated contact in the test bank of the connector. Relay 215 also closes a circuit traceable from ground through generator G5, resistance R,

working contact and armature 219, resting 220, conductor 38, The ringer 35 will contact and armature ringer 35 to ground.

operate as an indication that the desired connection has been established.

A further result of the energization of relay 215'is the'closurc of a ringing circuit traceable from ground, generator G, ring contact and and working contact, wiper 204 and the contact upon which .it is now resting, line conductor 47 substation A, line conductor 46, bank contact upon which wiper 201 is now standing and said wiper, working contact and armature.228, arn' ature 224 audits resting contact, upper winding of relay 225 to battery. The ringer at the called substation will op crate periodically. The ringing currcnt'will have no etlect upon relay 225 as the said relay is slow acting. \Vhen the called party answers, a path for direct current will be established at substation A 225 will. operate to close the springs holding circuit is thus completed "for the lower winding 01 relay 225, whereupon the said relay becomes fully energized and opcrates to remove generator and relay 225 from the called line and to connect the same through to the battery feed relay 227.

The subscriber at the called substation now receives talking battery over the "following circuit: From grounded conductor 152, armature 208 and its working contact, armature 226 and its working contact, lower winding relay 227, working contact and armature 221, over the previously traced cir cuit to substation A and back to armature 2 24 and its working contact, upper winding and the relay 1 lltl wi ll remove ground from the thirteenth con a circuit will be closed through relay 207 at tend a connection by means or a key K to a called line that is busy. In this connec &

oirelay 227 to battery. An identity tone is vises the called party that the call is from a special substation and that he must remain upon the line until the calling party answers. A further result of the energization of relay 22'? is the opening oil the circuit of ringer 35 at armature 220. The stopping of the ring is an indication to the calling subscriber that the called si'ibscriber has an swered. The calling subscriber will now remove his receiver and draw talking battery through the upper and lower windings of relay 5230 by way of armatures 205 and 206. The relay 230 energizes and removes the identity tone at ar 1: re lhe conversation' will now proceed desired.

When the conversation is completed, both parties will restore their receivers to the switch-hook, whereupon relay 227 will deenergize and again close the circuit to ringer 35. Ringer 35 will now operate as a reminder that the key K must be restored.

lVhen the key K is restored the circuits to relays R, R R and 135 are opened. Relay 135, upon deenergizing, will again connect lineconductors 36 and 37' to line switch C, at the san'ie time removing the protecting ground in the test bank of the connector, Relay 135, will also open the locking circuits of relays 215 and 225. Relay 215, upon deenergizing opens the circuit to the cut-oil relay oi the called line switch, at the same time removing the busying ground" from the test contact associated with line A. inrth'e test bank of the connector. v 215, also, opens the circuit to wipers 201 and, 20%, therefore, they will not interfere With the circuit upon which they are standing.

Relay The dcenergization of relays R. R and R tact in the bank accessible to wiper 202. All of the apparatus is now in normal position it the wipers of the finder switch S chances to be standing on the bank contacts associated with a certain called substation whenv the correspondmg key K is operated therame time that a circuit is closed through relay 2L0, Relay 207 will. operate to open the circuit'ot relay 2.1.0 before the latter has closed a circuit through to the stepping magnet.

An explanation will now be given of the operation should an attempt be made to extion, it will be assumed that the called substation s busy,.therefore, there will be a ground upon the thirteenth contact in theU bank accessible to wiper 203. When the key K isoper'ated, the finder switch will function as previously explained to advance its wipers into engagement with the thirteenth set of bank contacts. As the called line is busy a circuit is now traceable from ground on the thirteenth contact in the bank acces sible to wiper 2G3, wiper 2 2%, armature 216 audits working contact, (relay 211 not yet having deenergized), resting contact and armature 2231, busy relay 232 to battery. Relay 232, upon energizing, forms a locking circuit'tor itself lIHlQPQDCiQDt of the ground upon wiper This locking circuitmay be traced from grounded conductor 152, armature 208 and its working Contact, armature 214 and itsworlring contact, resting contact of springs controlled by armature 216 (relay illlhaving now deenergized), resting contact and armature 231, relay 232 to battery. it further result'of the operation of relay is the placing of busy tone on the callii Y line by way of armature 233 and its wo ng' cent-act, working Contact and armature 206, conductor 150, working contact and armature 148 to talking conductor 3T.

Since relay 215 does not energize at this time, there will be no operation of ringer 35. I The calling subscriber will eventually remove his receiver, whereupon he will receive the busy tone as an indicationthat the called line is busy. He then replaceshis receiver and restores the key K the release of the apparatus taking place in the usual manner.

I V fhile only one specially equipped substation has been shown, it'is to be understood that others may be provided it desirec.

The object and scope of the invention hav- 1 in been described what is considered to be h 7 new and what itis desired to haveprotected by Letters Patent w ll be pointed out more ,3 specifically in the appended claims.

What is claimed is:

1. In a telephone system, a subscribeids line extending from substation to the exchange and having two branches, switching: arrangements for extending one of said branches to any desired line in the exchange, a switching device in which the other branch erminates, circuit connections by means of hich a limited number of said lines are 'maoe accessible to said switching device, and neans by which the Slllf)SL"llbl on said first ncntioned line controls said switching device.

2. In a telephone system, a calling substation, a switch at the exchange individual to aid station, a train of switches at the eX- hange common to said calling station and ther stations, called stations accessible to aid calling station by way of said switch rain only, connections to such called stations eing established independent of said indigvidualswitch, and a plurality of preferred called stations which are accessible to-said matically operating said bell when the connection is established and before the called party answers.

14. In a telephone system, a calling subscribers line and a called subscribers line, automatic switching mechanism at the exchange controlled from the calling station for connecting said lines, a bell at the station on the calling line, means for automatically operating said bell when the connection is established and means for rendering said first means ineffective when the called party answers.

15. In a telephone system, a calling and a called line, automatic switching mechanism at the exchange controlled from the calling station for connecting said lines, the connection being established while the switchhook at the calling station remains in normal position, and means for automatically signalling the calling subscriber when the connection is completed.

16. In a telephone system, a calling and a called line, automatic switching mechanism at the exchange controlled from the calling station for connecting said lines, the connection being established while the switchhook at the calling station ren'iains in normal position, and means for automatically signalling the calling subscriber when the called subscriber answers.

17. In a telephone system, a calling and a called line, automatic switching mechanism at the exchange controlled from the calling station for connecting said lines, the connection being established while the receiver at the calling station remains on the hook, means for ringing the calling and called stations and for automatically stop-f ping the ringing operations when the called subscriber answers, and means for automati cally signalling the called subscriber after he removes his receiver in order to notify him to wait until the calling subscriber removes his receiver.

18. In a telephone system, a calling and a called line, automatic switching mechanism at the exchange controlled from the calling station for connecting said lines, the

connection being established while the receiver at the calling station remains on the hook, means for automatically signalling the calling subscriber when the connection is established by ringing the bell at the calling station, means for automatically signalling the called subscriber when said called subscriber answers and for stopping the first signalling operation at the same time, and means for stopping the second signalling operation when the calling party answers.

19. In a telephone system, a calling subscribers line and a called subscribers line, automatic switching mechanism atthe eX- change controlled from the calling station to connect said lines, a signal at the calling 21. In a telephone system, a calling and a called line, automatic switching mechanism at the exchange controlled trointhe calling station to connect said lines, a set of keys at the calling station constituting the means by which the control of said mechanism is ettected, a signal at the calling station, and means responsive when the called party hangs up for operating said signal until all operated keys are restored to normal.

22. In a telephone system, a subscribers line, two automatic switches at the exchange individual to said line, means "for operating either of said switches separately at the option ot the subscriber, connector switches accessible to one of said individual switches, ,and other subscribers lines niultipled in i he banks of said connector switches and the other one of said individual switches.

23. In a telephone system, a subscribers inc, an automatic switch atthe exchange ndividual to said line and controllable itliei'eover, connector switches, switching ,mechanism controlled over said line for connecting said line with any one of said coii- ,iiectors while said individual switch remains 1 normal position, and other subscribers 111168 inultipled in the banks of said connector {ISWltCliGS and said individual switch.

2 In a telephone system, a calling and a called liiie, two separate routes over which alking connections may be completed beween said lines, automatic switches at the tions are established all connections over each route being exclusive of any switch used in any connection established over the other route, and means whereby the subscriber on the calling line can control said switches as desired to set up connections over either route as set forth.

25. In a telephone system, a calling and a called line, two separate routes over which talking connections may be completed be tween said lines, automatic switches at the exchange by means of which such connec tions are established all connections over each route being exclusive of any switch used in any connection established over the other route, and there being a greater number of switches involved in a connection set up xchange by means of which such conned Cir over one route than there is'in a connection set up over the other route, and means whereby the subscriber on the calling line can control said switches as desired to set up connections over either route as set forth.

26. In a telephone system, a calling and a.

called line, two separate routesover which talking connections may be completed between said lines, automatic switches at the exchange by means or which such connections are established, a ringing tone, a signal at the station on the calling line, automatic means for giving said tone to the calling subscriber over one route when a connection is established, and means for antomatically operating said signal over the other route when the connection is established.

27. In a telephone-system, asubstation, a plurality of other substations, a switch individual to said first substation and having access to said other substations, a group of control conductors extending from said first substation to the exchange, and a set of relays energized in combinations over said conductors to control said individual switch to hunt for and connect a desired one of said other substations to said first substation.

28.111 a telephone system, a substation, a plurality of other substations, a switch individual to said first substation and having access to said other substations, and a set of keys at said first substation, one key for each substation to which said switch has access,

for controlling said switch to hunt for and connect desired one r said other substations with said first substation,

29. A switch control system comprising a series of. test conductors, a group of relays less in number than said conductors, an individual conductor tor each of said relays, and a set of keys equivalent in number to said test conductors for energizing said relays over their individual conductors in combi nations to close test circuits over said test conductors. V

30. A switch control system comprising a series or test conductors, a group or relays less in number than said conductors, set of keys equivalent in number to the number of said test conductors, a set of control conductors equivalent in number to the number of relays and each control conductor being individual to one of said relays, and circuit connections whereby when any one of said.

keys is operated a certain combination of called line,

said relays energize over their individual control conductors to place a test'potential on the test conductor corresponding to. the operated key.

31. In a telephone system, a subscribers line, two automatic progressively movable switches at the'exchange individual to said line, and means at the station on said line for operating either of said switches separately at the option of the subscriber.

32. In a telephone system, a subscribers line, two single level automatic hunting switches at the exchange individual to said line, and means for starting either of said switches separately at the option of the subscriber.

33. In a telephone system, a calling subscribers line, two single level automatic hunting switches at the exchange individual to said line, called subscribers lines, the first of said switches adapted when operated to extend connection in the direction of any one of said called lines and the second switch adapted when operated to completea connection to any one of said called lines, and means for operating either of said switches separately at the option or the subscriber on the calling line."

34:. In a telephone system, a calling and a two separate routes over which talking connections may be completed between said lines, automatic switches at the exchange by means of which such connections are established, there being a plurality of switches involved in one route and only a single switch in the other route, and means whereby the subscriber on the calling, line can control said switches as desired to set up connections over either route as set forth.

35. In a telephone system, a calling and a called line, two separate routes over which talking connections rnav be completed between said lines, automatic switches at the exchange by means'of which such connections are established, there being a greater number of switches involved in a connection set up over one route than there is in a connection set up over the other route, and means whereby the subscriber on the calling line can control said switches as desired to setup connections over either route as set forth. 1 f y In witness whereof. I hereunto subscribe my name this 12th day of February, A. D.,

CLARENCE E. LOMAX. 

